Conveyor systems having article supports that comprise a trolley and a rotatable article holder or shackle are well known in the poultry processing industry. One suitable example is described in European patent 0786208, which discloses a shackle for suspending poultry by their legs for movement by a conveyor track of a poultry processing line past and through individual processing stations. More specifically, a trolley assembly is supported and guided along a conveyor track and moved therealong by a transport chain. Poultry suspension hooks are rotatably mounted to the trolley and an associated turning gear is adapted to cooperate with turning features along the track to rotate the turning gear and thereby the poultry suspension hooks between predetermined rotary positions or orientations. At the location of individual processing stations, the turning gear is usually retained between opposite parallel side guides to inhibit any rotation when a suspended poultry carcass is being processed at the processing station. In between the processing stations, however, these parallel side guides may be interrupted or otherwise not be present. The side guides are also interrupted where the turning gear is engaged by turning features at a turning station to effect its rotation to a desired orientation.
The turning gear, which is a substantially square body, has slots extending inwardly from its corners. These slots are engageable by turning pins at turning stations positioned along the conveyor path to rotate the turning gear and its associated shackle to a desired orientation. A yieldable indexing arrangement between the trolley and the turning gear ensures that the desired orientation is retained as the assembly moves further along the track. This is of particular importance at locations where the lateral side guides are interrupted. The typical yieldable indexing arrangement includes a spring biased ball and socket assembly with a cavity for holding the ball and spring on one of the relatively rotatable parts and a ball receiving recess or detent on the other relatively rotatable part. The ball snaps into a detent when the turning gear is in predetermined indexed orientations to maintain the turning gear and shackle yieldably in these orientations. Other mechanical arrangements by be used.
The characteristics of mechanical tension springs of these indexing assemblies are not always compatible with the yieldability requirements of rotatable article support assemblies. It is important from a safety perspective, for instance, that the indexing assemblies give way when human beings accidentally obstruct a suspended article moving along the path of conveyance. Thus while relatively firm indexing is required to hold the turning gear and shackle in its indexed orientations, there is also a somewhat conflicting need for relatively forceless disturbance of the turning gear and shackle away from the indexed orientations when accidentally disturbed, and to return them thereafter back to their indexed orientation.
There is therefore a need for an improved article support assembly and aligning station for use in a processing conveyor. In a more general sense there is a need for such a support assembly and aligning station that overcomes or ameliorates at least one of the disadvantages of the prior art. There is a related need for alternative structures which are less cumbersome in assembly and operation and which moreover can be made relatively inexpensively. Alternatively a need exist at least to provide consumers with a useful choice. It is to a method and apparatus that addresses these and other needs that the present invention is primarily directed.